Flashlamp

ABSTRACT

A percussively triggered flashlamp is made of a lighttransmitting envelope, such as glass, with a metal tube extending therefrom and holding the percussive material, and a loose fitting of a combustible material such as shredded zirconium, in an atmosphere of combustion-supporting gas, such as oxygen. The percussive material has particles of a metal such as zirconium mixed therewith to incandesce and ignite the zirconium shreds. The percussive material can be detonated by striking or squeezing the metal tube containing it, as with a firing pin. A wire can extend into the metal tube to act as an anvil against which the percussive material is forced by the firing pin, and can also serve as a means of fitting the tube with percussive material during manufacture of the lamp. The lamp can be used in a flashcube, preferably by modifying the base to insure the presence of a firm background behind the metal tube and against which the firing pin can force it especially if there is no wire or other anvil present in the tube. To facilitate miniaturization of the camera with which the flashlamp can be used, and to permit interchangeability of different size cubes, the metal tube can be offset from the axis of the envelope and the envelope positioned so the tube is set nearer to the axis of the flashcube.

United States Patent Primary Examiner-Charles .l. Myhre Atmrneys Norman J. OMalley and Laurence Burns ABSTRACT: A percussively triggered flashlamp is made of ,i light-transmitting envelope, such as glass, with a metal tube extending therefrom and holding the percussive material, and a loose fitting ofa combustible material such as shredded zirconium, in an atmosphere of combustion-supporting gas, such as oxygen. The percussive material has particles of a metal such as zirconium mixed therewith to incandcsce and ignite the zirconium shreds. The percussive material can be detonated by striking or squeezing the metal tube containing it, as with a firing pin. A wire can extend into the metal tube to act as an anvil against which the percussive material is forced by the firing pin, and can also serve as a means of fitting the tube with percussive material during manufacture of the lamp, The lamp can be used in a flasheube, preferably by modifying the base to insure the presence of a firm background behind the metal tube and against which the firing pin can force it especially if there is no wire or other anvil present in the tube. To facilitate miniaturization of the camera with which the flashlamp can be used, and to permit interchangeability of different size cubes, the metal tube can be offset from the axis of the envelope and the envelope positioned so the tube is set nearer to the axis ofthe flashcube.

PATENTED me] new SHEET 1 OF 2 luvs/v r, m

PATENTEU M151 7 R971 3,600,120

SHEET 2 0F 2 R0 Koriy r N vEv-ng FLASHLAMP FIELD OF INVENTION This invention relates to flashlamps, which are usually lamps having a filling of a combustible material and a combustion-supporting gas in a light transmitting envelope with an electrical igniter, and relates in particular to the igniting of the combustible material in such lamps by a percussive mixture which can be detonated by a blow, such as that deliverable by a firing pin.

BRIEF DISCUSSION OF PRIOR ART Percussively-ignited flashlamps have many advantages over prior flashlamps which use a heated electrical filament to ignite the combustible material. The need for the filament is eliminated as well as the electrical battery and its accompanying circuitry. At the same time, when the lamp is used for illuminating an object for photography, the possibility of the loss of a picture by failure of the battery to ignite the lamp is eliminated. The battery often becomes dead when the camera is unused for a while, and a picture can be lost if the photographer doesnt notice this until the failure of the lamp to ignite.

One kind of percussively-actuated fiashlamp is shown in a copending patent application Ser. No. 662,755 filed Aug. 23, 1967 by Kopelman and Hay. The lamp specifically shown in that application is arranged for actuation by a blow on the bottom, although many features of the device could be used with actuation by a blow in another direction. Actually, for many purposes, a lamp actuated by a blow exerted sidewise upon it would be desirable, and a lamp for side actuation is shown in the present application.

BRIEF SUMMARY OF THE INVENTION We have discovered that a flashlamp can be made with a light-transmitting envelope, for example of glass, having a sealed metal tube of smaller diameter sealed to its bottom portion and extending from it. The light-transmitting envelope can have a loose filling of shredded zirconium foil, or of other suitable material, in the usual manner for flashlamps, together with a filling of a combustion supporting gas such as oxygen. The metal tube has a filling of percussive material, such as the mixture of phosphorus and potassium chlorate described in a copending application Ser. No. 662,756, now abandoned filed Aug. 23, 1967 by Seeger and Kopelman with the metallic zirconium particles mentioned therein.

The percussive material may be detonated by squeezing the tube with pincers or the like or by hitting it with a firing pin on one side to force the other side against an external anvil. However, I have discovered that a solid cylindrical wire inserted in the metal tube and of smaller diameter than the inside diameter of the tube, the space between the outside of the wire and the inside of the tube being filled with percussive mixture and metal particles, is very effective, and during the manufacture of the lamp, the percussive material can be applied to or coated on the wire, which thus serves as a means of getting the mixture into the tube. I have found that the less percussive material used the less the detonation affects the lumen-time distribution. The wire serves to lessen the amount of percussive material needed.

The lamp can be used in the so-called fiashcube, where a number of lamps are arranged in reflectors set facing outwardly around a central axis and supported from a base. When so used the base can be cut away in front of, the metal tube so that a firing pin can strike it from the side and push it against the base as against an anvil, the base thus acting as an anvil.

The metal tube can ordinarily be set along the axis of the light-transmitting envelope, but in some cases it may be desirable to have it offset from the axis and placed along a line which passes through the axis of the fiashcube and on the side of the lamp nearest the center of the flashcube, so that the tubes will set along the circumference of a smaller circle, and the flashcube be useful as a replacement for a smaller one having the tubes along the axes of the lamps. Cameras utilizing lamps so offset from the axis will thus be able to utilize equally effectively smaller cubes if the distance from the center axis of the cube to the metal tube is the same.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the invention will be apparent from the following specification, taken in connection with the accompanying drawing, in which:

FIG 1 is a lamp according to one embodiment of my invention;

FIG. 2 is a sectional view of another embodiment;

FIG. 3 is a sectional view of still another;

FIG. 4 is an elevation, partly in section, of the lamp in the base of a flashcube suitable for a side-striking firing pin;

FIG. 5 is a schematic bottom view of a flashcube using lamps with the projecting metal tube at the center of the tube axis; and

FIG. 6 is a schematic bottom view of a flashcube using lamps with the projecting metal tube ofiset from the tube axis and nearer to the center of the flashcube.

COMPLETE DESCRIPTION OF EMBODIMENTS In FIGS. 1 and 2, a lamp 1 has a light-transmitting tubular envelope 2, which may be for example of glass, with the soft metal tube 3, of smaller diameter than the tubular envelope 2, sealed to the envelope at its bottom. The tube 3 is in communication with the envelope 2 near the top 4 of the tube 3 but is closed at the bottom 5 of the tube 3. The glass envelope is sealed at the exhaust tip 6, and contains a suitable quantity of combustible, for example shredded zirconium foil 7, and a filling of a combustion supporting gas, such as oxygen at high pressure, generally several atmospheres, for example six atmospheres.

The percussive mixture 8, which can be the potassium chlorate and phosphorous, together with metal particles, shown in the Seeger and Kopelman patent application Ser. No. 662,756, now abandoned to which reference has been made above, is in the tube 3, along the axis of which is the hard metal wire 9, which can be of tungsten. This wire acts as an anvil against which the percussive mixture will be pushed when the tube 3 is squeezed by an externally applied force, as from a firing pin. The wire 9 preferably extends up into the shredded foil 7, and also serves as a means of introducing the percussive mixture into the tube by precoating the wire prior to insertion. The wire 9 can be omitted if an external anvil is provided.

In FIG. 1, the tube 3 is of copper, being sealed to the glass envelope 2 in the well-known manner of so-called Housekeeper seals." It may also be No. 4 alloy, a nickel chromium steel. In FIG. 2, the tube 3 is of so-called No. 4 alloy, a nickel-chromium steel capable of direct sealing to soft glass, which is used in the envelope. The No. 4 alloy can be sealed to the glass whether it is the outside or inside member of the seal.

FIG. 3 shows a further variation of the lamp. In this the various parts have the same reference numerals as before, except that the glass envelope 2 is here composed of two parts, a tubular glass envelope l0 closed at its bottom portion by a substantially flat glass waver 11 to which the tube 3 is sealed. This construction is economical and allows a somewhat larger volume suitable for increased zirconium till, thus resulting in increased light output. It also allows for easy displacement of the metal tube from its center axis.

In FIG. 4, the lamp of FIG. 3 is shown seated on a base member 12, shown in section, the base member being similar to the base of an ordinary flashcube, but having a cutaway portion so that a striking pin can strike the tube 3 at point 13 and force it back against the base at point 147 The lamp can be affixed to the base in some convenient manner, as be being firmly glued to it.

FIG. 5 shows a bottom view of a flashcube having a base 12 with the lamp 1 set on the base inside the cube, the base having arcuate cutouts 16 into which the depending tubes 3 are inserted. The middle tubing 17 extends downward from the base for attachment to a camera. The base can be of plastic.

in FIG. 6, the lamps l are shown with the depending metal tubes 3 offset from the axis of the base 12 of flashcube 15, so that they are set around a smaller circle, thus being useful in a camera or receptacle designed for a smaller flashcube which might have its tube 3 along the axis of its envelope. This helps to make flashcubes of different sizes interchangeable, and allows miniaturization of the camera because of the smaller circle around which the tubes 3 are placed.

What i claim is:

1. A flashlamp comprising a light transmitting envelope, a hollow metal tube sealed thereto and in communication therewith, a filling of combustible material and a combustionsupporting gas in said envelope, said envelope having a maximum lateral dimension several times that of the lateral dimension of said metal tube, a wire extending into said tube and a quantity of percussive material and metal particles in said hollow metal tube between the outer surface ofthe wire and the inner surface of the metal tube.

2. The lamp of claim 1 in which the metal tube is sealed to the glass envelope at a position offset from the axis of the envelope and affixed to a lamp-holding base at a position nearer the center of the base than would result if positioned from the axis of the lamp.

3. The flash lamp of claim I, in which the hollow metal tube is of soft metal.

4. The flash lamp of claim 1, in which the percussive material is coated on said wire.

5. A flashlamp comprising a light transmitting envelope, a hollow metal piece sealed thereto and in communication therewith, a filling of combustible material and a combustionsupporting gas in said envelope, and a quantity of percussive material and metal particles in said hollow metal piece, said envelope having a maximum lateral dimension several times that of the lateral dimension of said metal piece, and a base to which said lamp is affixed, the hollow metal piece of said lamp being seated against a portion of said base and in position to be forced against said portion when struck from the side opposite it.

6. The lamp of claim 5. and a plurality of other lamps arranged in the same manner on the same base, the tubes being set along the circumference of a circle substantially concentric with the base and transverse to the plane of the base. 

1. A flashlamp comprising a light transmitting envelope, a hollow metal tube sealed thereto and in communication therewith, a filling of combustible material and a combustion-supporting gas in said envelope, said envelope having a maximum lateral dimension several times that of the lateral dimension of said metal tube, a wire extending into said tube and a quantity of percussive material and metal particles in said hollow metal tube between the outer surface of the wire and the inner surface of the metal tube.
 2. The lamp of claim 1 in which the metal tube is sealed to the glass envelope at a position offset from the axis of the envelope and affixed to a lamp-holding base at a position nearer the center of the base than would result if positioned from the axis of the lamp.
 3. The flash lamp of claim 1, in which the hollow metal tube is of soft metal.
 4. The flash lamp of claim 1, in which the percussive material is coated on said wire.
 5. A flashlamp comprising a light transmitting envelope, a hollow metal piece sealed thereto and in communication therewith, a filling of combustible material and a combustion-supporting gas in said envelope, and a quantity of percussive material and metal particles in said hollow metal piece, said envelope having a maximum lateral dimension several times that of the lateral dimension of said metal piece, and a base to which said lamp is affixed, the hollow metal piece of said lamp being seated against a portion of said base and in position to be forced against said portion when struck from the side opposite it.
 6. The lamp of claim 5, and a plurality of other lamps arranged in the sAme manner on the same base, the tubes being set along the circumference of a circle substantially concentric with the base and transverse to the plane of the base. 